2005/07/28 by Nuno Loureiro, N. F. Loureiro, S. C. Cowley +4 · 8 citations
Physics and Astronomy · #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Physics of Superconductivity and Magnetism #astro-ph #physics.plasm-ph #physics.space-ph
paper · pdf · doi:10.1103/physrevlett.95.235003
published as Phys.Rev.Lett.95:235003,2005 · revtex4, 4 pages, 18 figures
arxiv created 2005/07/28 · openalex publication_date 2005/11/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study the nonlinear evolution of the resistive tearing mode in slab geometry in two dimensions. We show that, in the strongly driven regime (large \ensuremathΔ^\ensuremath'), a collapse of the X point occurs once the island width exceeds a certain critical value \ensuremath∼1/\ensuremathΔ^\ensuremath'. A current sheet is formed and the reconnection is exponential in time with a growth rate \ensuremath∝\ensuremathη1/2, where \ensuremathη is the resistivity. If the aspect ratio of the current sheet is sufficiently large, the sheet can itself become tearing-mode unstable, giving rise to secondary islands, which then coalesce with the original island. The saturated state depends on the value of \ensuremathΔ^\ensuremath'. For small \ensuremathΔ^\ensuremath', the saturation amplitude is \ensuremath∝\ensuremathΔ^\ensuremath' and quantitatively agrees with the theoretical prediction. If \ensuremathΔ^\ensuremath' is large enough for the X-point collapse to have occurred, the saturation amplitude increases noticeably and becomes independent of \ensuremathΔ^\ensuremath'.